/*
 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 1999-2002,2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/*
 * WARNING: because java doesn't support multi-inheritance some code is
 * duplicated. If you're changing this file you probably want to change
 * DeferredAttrNSImpl.java at the same time.
 */

package com.sun.org.apache.xerces.internal.dom;

/**
 * Attribute represents an XML-style attribute of an
 * Element. Typically, the allowable values are controlled by its
 * declaration in the Document Type Definition (DTD) governing this
 * kind of document.
 * <P>
 * If the attribute has not been explicitly assigned a value, but has
 * been declared in the DTD, it will exist and have that default. Only
 * if neither the document nor the DTD specifies a value will the
 * Attribute really be considered absent and have no value; in that
 * case, querying the attribute will return null.
 * <P>
 * Attributes may have multiple children that contain their data. (XML
 * allows attributes to contain entity references, and tokenized
 * attribute types such as NMTOKENS may have a child for each token.)
 * For convenience, the Attribute object's getValue() method returns
 * the string version of the attribute's value.
 * <P>
 * Attributes are not children of the Elements they belong to, in the
 * usual sense, and have no valid Parent reference. However, the spec
 * says they _do_ belong to a specific Element, and an INUSE exception
 * is to be thrown if the user attempts to explicitly share them
 * between elements.
 * <P>
 * Note that Elements do not permit attributes to appear to be shared
 * (see the INUSE exception), so this object's mutability is
 * officially not an issue.
 * <P>
 * DeferredAttrImpl inherits from AttrImpl which does not support
 * Namespaces. DeferredAttrNSImpl, which inherits from AttrNSImpl, does.
 *
 * @author Andy Clark, IBM
 * @author Arnaud  Le Hors, IBM
 * @xerces.internal
 * @see DeferredAttrNSImpl
 * @since PR-DOM-Level-1-19980818.
 */
public final class DeferredAttrImpl
    extends AttrImpl
    implements DeferredNode {

  //
  // Constants
  //

  /**
   * Serialization version.
   */
  static final long serialVersionUID = 6903232312469148636L;

  //
  // Data
  //

  /**
   * Node index.
   */
  protected transient int fNodeIndex;

  //
  // Constructors
  //

  /**
   * This is the deferred constructor. Only the fNodeIndex is given here.
   * All other data, can be requested from the ownerDocument via the index.
   */
  DeferredAttrImpl(DeferredDocumentImpl ownerDocument, int nodeIndex) {
    super(ownerDocument, null);

    fNodeIndex = nodeIndex;
    needsSyncData(true);
    needsSyncChildren(true);

  } // <init>(DeferredDocumentImpl,int)

  //
  // DeferredNode methods
  //

  /**
   * Returns the node index.
   */
  public int getNodeIndex() {
    return fNodeIndex;
  }

  //
  // Protected methods
  //

  /**
   * Synchronizes the data (name and value) for fast nodes.
   */
  protected void synchronizeData() {

    // no need to sync in the future
    needsSyncData(false);

    // fluff data
    DeferredDocumentImpl ownerDocument =
        (DeferredDocumentImpl) ownerDocument();
    name = ownerDocument.getNodeName(fNodeIndex);
    int extra = ownerDocument.getNodeExtra(fNodeIndex);
    isSpecified((extra & SPECIFIED) != 0);
    isIdAttribute((extra & ID) != 0);

    int extraNode = ownerDocument.getLastChild(fNodeIndex);
    type = ownerDocument.getTypeInfo(extraNode);
  } // synchronizeData()

  /**
   * Synchronizes the node's children with the internal structure.
   * Fluffing the children at once solves a lot of work to keep
   * the two structures in sync. The problem gets worse when
   * editing the tree -- this makes it a lot easier.
   */
  protected void synchronizeChildren() {
    DeferredDocumentImpl ownerDocument =
        (DeferredDocumentImpl) ownerDocument();
    ownerDocument.synchronizeChildren(this, fNodeIndex);
  } // synchronizeChildren()

} // class DeferredAttrImpl
